Acknowledgments xvii List of Abbreviations xix Introduction 1 Chapter 1 The Basic Physics of Ultrasound 5 Sound Waves 5 Describing Waves 9 Energy in a Sound Wave 11 Ultrasound Pulses 12 Energy Spectrum of a Pulse 13 Bandwidth 14 Speed of Sound (C) 16 Characteristic Acoustic Impedance, Z0 20 Energy in a Sound Wave 22 Decibels 23 Chapter 2 The Interaction of Ultrasound with Tissue 25 Reflection and Transmission at a Plane Interface 25 Poor Visualisation 29 Scattering 30 Attenuation 34 The Journey of the Ultrasound Pulse 37 User Control 37 References 38 Chapter 3 Beam Shapes 39 Simple Beam Shape Model 40 Huygen''s Wavelet Model and Diffraction 43 Focusing 44 Beam Forming with Transducer Arrays 47 Beam Steering 50 Electronic Focusing 52 Resolution 54 Clutter 58 Reference 58 Chapter 4 The Ultrasound Probe 59 The Transducer 59 Backing Layer 62 Matching Layer 63 Front Face Lens 65 Wide Band Transducers 65 Construction of an Array 66 CMUT Technology 66 1-D, 1.5-D, and 2-D Arrays 68 References 72 Chapter 5 Image Formation 73 Image Modes 74 Linear Image Formation 76 3D Imaging 80 Cine Loop 82 Endoprobes 82 Choosing A Probe 84 Focusing 84 Increasing Frame Rate 86 User Control 86 Ultrasound Harmonics 89 Coded Excitation 92 References 94 Chapter 6 The B-Mode Scanner 95 Transmission Side of a Scanner 95 User Controls 96 Receive Side of a Scanner (Rx) 97 Advantages of Digitising 101 Dynamic Range and Transfer Function (Greyscale Mapping) 102 Contrast Resolution 106 User Controls 106 Image Memory 106 Frame Freeze 106 Read and Write Zoom 107 Image Processing 108 User Control 108 Chapter 7 Image Quality and Artefacts 111 Acoustic Window 111 Frame Rate: Frames Per Second (fps) 112 Interlacing Scan Lines 113 Interpolation - Writing in ''Extra Lines'' 114 Speckle 115 Frame Averaging or Persistence 116 User Control 117 Spatial Compound Imaging 117 Adaptive Filtering 118 Artefacts 122 Speed of Sound Artefacts 122 Attenuation Artefacts 127 Reflection Artefacts 130 Anisotropy 134 Beam Shape Artefacts 135 Temporal Artefacts 137 Final Example 139 References 140 Chapter 8 Principles of Doppler Ultrasound 141 The Doppler Effect 141 The Doppler Equation 143 Duplex Ultrasound 144 CW Doppler 145 CW Doppler Summary 152 Pulsed Wave Doppler (PW Doppler) and Range Gating 152 Intrinsic Spectral Broadening (ISB) 160 Question: What Doppler Angle Should We Use? 162 User Controls 163 Peak Velocity Envelope 165 Average Velocity 167 Doppler Artefacts 170 References 173 Chapter 9 Principles of Colour Doppler Ultrasound 175 Autocorrelation 177 Colour Scale 180 Frame Rate 181 User Controls 181 CDU and the Doppler Angle 183 Colour Aliasing 183 User Controls 185 Discrimination of Stationary Targets 187 User Controls 188 Power Doppler (PD) 188 CDU Artefacts 190 Colour Sensitivity 192 Presets 194 Colour M-Mode 194 Tissue Doppler Imaging (TDI) 194 Myocardial Strain Imaging 197 Speckle Tracking Echocardiography STE 199 References 202 Chapter 10 Making Measurements 203 Accuracy 204 Precision 204 How Accurate or Precise Do We Need To Be? 205 Reproducibility 205 Systematic and Random Errors 206 Ultrasound Measurements in Practice 206 Physical Constraints 207 Sonographer-Based Constraints 209 Principles for Making Reliable Measurements 209 Measurement of Circumference, Area, and Volume 213 Doppler Waveform Measurements 216 Waveform Indices 219 Colour Doppler Ultrasound 221 Measurement of Volume Flow Q 221 References 224 Chapter 11 Safety and Quality Assurance 225 Energy, Power, and Intensity 226 Measuring Intensity 227 Intensity 227 Factors Affecting Damage Potential 230 Thermal Effects 231 Thermal Index (TI) 232 Transducer Self-Heating 234 Nonthermal Effects 235 Radiation Force 235 Streaming 235 Cavitation 236 Mechanical Index (MI) 239 Alara 239 Contrast Agents 240 Quality Assurance and Routine Checks 241 Suggested Routine User Checks 241 The Use of Test Objects 244 Personal Risk Management 245 New Techniques in Ultrasound 246 References 247 Chapter 12 Advanced Topics 249 Contrast Agents (CA) 249 Behaviour of Bubbles in the Ultrasound Field 251 Contrast Agent Harmonics 252 Flashing 254 Advanced Micro-Bubble Techniques 255 B-Flow Blood Vessel Imaging 256 Doppler Measurement of Pressure Gradients 260 Advanced Image Processing 261 Artificial Intelligence 261 Segmentation 262 Examples (1-3) 262 Computer-Aided Diagnosis (CAD) 263 Diagnosis with Cad 268 Fusion Imaging 269 Needle Visualisation and Guidance 271 References 274 Chapter 13 Ultrafast Ultrasound 277 Synthetic Aperture Imaging (SA) 278 Plane-Wave Beamforming 279 Summary 283 Speed of Sound Correction 283 Ultrafast Doppler 286 Vector Flow Imaging (VFI) 291 References 298 Chapter 14 Elastography 301 Background Theory 302 Elastography 303 Methods of Applying The Distorting Force 303 Strain Elastography (SE) 303 User Controls 307 SE Artefacts 310 Acoustic Radiation Force Impulse Imaging (ARFI Imaging) 314 Strain Ratio 316 Shear Wave Elastography (SWE) 316 Point SWE (PSWE) 320 Supersonic Shear Imaging (SSI) 322 Shear Wave Compounding 323 SWE Artefacts 325 References 326 Appendix 1: Knobology 329 Appendix 2: Handling Equations and Decibels 335 Appendix 3: The Unfocused Transducer Beam Shape 345 Index 349.